U.S. Pat. No. 4,318,641 granted to Hogervorst on Mar. 9, 1982, and assigned to Shell Oil Company discloses a suction anchor. Briefly, a suction anchor comprises a length of steel tubing having a relatively large diameter and a relatively long length, for example, a typical suction anchor might be 12 feet in diameter and 60 feet in length. The suction anchor has an open bottom and a top equipped with structure which allows water to be pumped out of the interior of the suction anchor thereby establishing a pressure differential which causes the suction anchor to penetrate the seafloor. The suction anchor is adapted for subsequent removal from the seafloor by pumping water into the interior thereof.
The Hogervorst '641 Patent discloses in FIGS. 1 and 2 a first pumping apparatus and in FIG. 7 a second apparatus which may be used to effect the flow of water out of or into a suction anchor. Although mentioning structure for clamping the pumping apparatus to the suction anchor, the details of the clamping apparatus are not further disclosed. It is not at all clear from the specification of the Hogervorst '641 Patent that the pumping apparatus described therein can be actuated to effect rapid reversal of the direction of water flow relative to the suction anchor which may be necessary to free the suction anchor from the seafloor in the event that the material into which the suction anchor has been installed has become consolidated around the interior and exterior walls thereof. Also, the apparatus disclosed in FIG. 7 of the Hogervorst '641 Patent for guiding the pumping apparatus downwardly from the surface and into engagement with the suction anchor is not considered adequate for use in deep water installations.
The present invention comprises a pumpskid useful in conjunction with a remotely operated vehicle for installing suction anchors in deep water installations. In accordance with the broader aspects of the invention, the pumpskid is provided with structure for securely clamping the pumpskid in engagement with the suction port of the suction anchor. The pumpskid is provided with remotely operable valving apparatus for causing a pump mounted on the pumpskid to pump water either out of or into the suction anchor as may be required. The valving apparatus may be operated to rapidly reverse the direction of water flow relative to the anchor thereby dislodging a suction anchor which may have become too firmly imbedded in the seafloor.